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By M. F. Boos

The Portland beryl-mica district, Middlesex County, Conn., comprises three deposits investigated by the Bureau of Mines in 1943. The Gotta-Walden deposit is in a pegmatite dike 4 to 20 feet thick, which cuts gneiss and schist. In general, the hanging wall is rich in mica and beryl with some feldspar, quartz, and garnet. The central core is usually high in quartz and feldspar, with relatively little mica and beryl. The footwall comprises quartz and feldspar, with varying amounts of mica and some beryl. The beryl crystals range in color from green to almost golden and have a maximum diameter of inches. Results of surface trenches indicate a beryl content of 0.81 percent for the pegmatite. A small production of beryl, feldspar, and scrap mica has been made from the deposit.

Jan 1, 1949

By R. F. Droullard

The Bureau of Mines has developed test facilities for use in a research program that deals with radiation hazards in mining. This report describes the radon test chamber located at the Denver Research Center and the Twilight experimental mine located near Uravan, CO.

Jan 1, 1984

By E. D. Eastman

There are three researches upon the specific heat of water vapor by the method of explosion that are sufficiently advanced in technique and suitable in plan to justify careful study of their results , with the double purpose of fixing the best available experimental values and indicating the attainable accuracy of the method. These three researches comprise the work of Pier , Bjerrum , and Siegel.5 The work of earlier date than Pier's suffers from obvious inaccuracy of measurement , while the experiments more recent than Siegel's , such as those of Womersley6 , of Bone and his collaborators , and of Maxwell and Wheeler , 8 are for the most part not well designed for the accurate determination of the heat capacities in question . Some of the errors to which they are especially subject have been discussed by David and by David and Thorp.

Sep 1, 1930

By G. L. Oldright

This paper is the second of a series that is to appear on smelting in the lead blast furnace. The objects of this investigation are to determine the conditions obtaining within the blast furnace by direct experimentation, and to correlate the behavior of the furnace at various times with the main factors governing the operation of the blast furnace, and metallurgical losses. The writers wish to express their appreciation to the management of the International Smelting Company at Tooele. Utah, for their kind cooperation which made possible the assembling of these data.

Jan 1, 1929

By Sterling J. Anderson

Through the use of nondestructive testing techniques, the Bureau of Mines is pursuing a goal of improving the efficiency of the rock excava-tion process. Toward this end, 44 laboratory tests were conducted to identify a practical method of monitoring fracture development in rock, as caused by an excavation tool. An acoustic emission CAE) transducer was used to monitor the test samples as they were loaded. The signal from this instrument was recorded in real time along with the radial and axial loads generated by the fracturing device. Through the review of these signals on a common-time base, it was possible to see the relationship between the developing fracture and the loading conditions. As a part of the posttesting investigations, samples that were pletely fractured were sawn and ground to expose the fractures. examination of these samples allowed approximations to be made incom-Visual of the total surface created. Surface area approximations were also made for the completely fractured samples. Quantitative analyses· of the AE signals were conducted for comparisons with the calculated surface areas.

Jan 1, 1987

By Frank C. Morris

It is generally recognized that the productivity and ultimate recovery of an oil well may be reduced as a result of reduction in permeability of the sand at the well bore by invasion of filtrates and clay particles from drilling fluids. As a means of determining whether a sand has been "damaged" from these sources, several investigators2 3 4 5/ have developed methods of analysis based on the rate of increase in bottom-hole pressure while a well is shut in. Because of growing recognition of the importance of completion practices as related to the quantity of oil that may be recovered from wells, the Bureau of Mines has studied completion practices in California and the Midcontinent area. Well-interference and pressure-buildup tests were completed Ear seven wells in the Scurry Reef field to determine the effective permeability in the reservoir.6/ Also, a study was made of the pressure-decline curves obtained from 35 water-input wells in 5 different production areas of northeastern Oklahoma and eastern Kansas.7/

Jan 1, 1957

From 1886, the first year shipments were recorded, until 1939, the Leadville district produced over 3,500,000 long tons of manganiferous ore. Of this total, metallurgical-type ores comprised 27 percent and manganiferous iron ores suitable for fluxing in lead smelters made up 73 percent. In 1939, the Bureau of Mines, as part of the strategic minerals investigative program being conducted at the time, requested the Mineral Industries Survey Section of the Mining Division to make a comprehensive study of the manganese resources of the Leadville area. This investigation, owing to the caved and flooded condition of the underground mine workings, was necessarily confined to a study of old maps, production records, and geological reports, and the results were published as an Information Circular in July 1940.

Jan 1, 1949

By R. A. Friedel

THE UTILIZATION by the Bureau of Mines of infrared and ultraviolet-visible spectrometry in connection with coal research has led to some basic improvements in methods, including a calibration method, a quantitative assessment of infrared spectral energy sources, and the development and perfection of infrared filters and cells. The adoption of a micropipet method to flush organic samples into absorption cells permits the investigation of vapors from organic liquids and the identification of volatile organic compounds. The spectral method has been used to investigate the infrared spectra of metal chelates, the charge-transfer complexing properties of aniline and nitrobenzene, an infrared method for determining the presence of methane in coal-mine air that has been adopted for use in enforcing the regulations of the National Coal Mine Safety Act, and atmospheric pollution including smog and odor-causing oxidation and decomposition of organic materials. Correlation of spectra and structure of organic compounds, particularly aromatics, was studied.

Jan 1, 1966

By A. B. Needham

A number of the pegmatites in the southern Black Hills of western South Dakota contain sheet mica; and as the demand increased during World War II the area became an important producer of strategic qualities of mica. During this period of maximum activity, the U. S.. Geological Survey made detailed studies of the geological structural control, the mineralogical associations, and the production Of many pegmatites in the Black Hills. On the basis of results of this study, and at the suggestion of the Geological Survey, several of the pegmatites were examined by the Bureau of Mines, and a few were selected for further investigation. Accordingly, the White Bear, Silver Dollar, Buster Dike, and Hot Shot mines were diamond-core-drilled in 1947. The Hot Shot mine was investigated further by deepening the shaft and crosscutting the pegmatite in 1948. The mica-bearing deposits occur in lenticular intrusions of pegmatite in schists of various mineral composition. Eleven diamond-drill holes, totaling 2,111.4 feet in length, were completed on the four deposits. The shaft on the Hot Shot deposit was deepened 44 feet to the 112-foot level, and crosscuts were driven from the bottom of the shaft to the hanging Wall and foot wall of the pegmatite. This publication briefly describes the location, ownership, and history of the deposits and gives details of the work done by the Bureau of Mines and the Geological Survey.

Jan 1, 1950

By August J. Kwitowski

This Bureau of Mines report summarizes the development of a protective operator compartment for a new generation thin-seam mobile bridge carrier. The developed compartment is commercially available and is currently employed on approximately 15 bridge carriers used in the mining industry. The design of the compartment, which employed human factors engineering and small- and full-scale mockup models, is fully described. Details of the compartment's fabrication, evaluation, and demonstration in a commercial low-seam coal mine are also provided.

Jan 1, 1986

By V. E. Erwin, W. W. Adams, E. V. Walters

"Increased production of explosives in the United States in 1933 compared with 1932 is shown by statistics compiled by the Demographical Division, Health and Safety Branch, United States Bureau of Mines. The figures relate only to explosives used for industries purposes, such as mining, quarrying, and road building, and do not cover nonindustrial explosives, such as ammunition or fireworks. Industrial explosives include black blasting powder, permissible explosives, 5 and high explosives other than permissibles figures in the tables of this report were compiled from reports covering sales by the individual companies manufacture of explosives in the United States in 1933. Because of the close agreement among the several series of figures, the quantity of explosives sold is considered as reflecting production and consumption, and the three terms ""sales"", ""production"", and ""consumption"" are used interchangeably in the discussion unless otherwise stated.Of the principal industries that use high construction operations accounted for the largest percentage of increase in consumption during 1933; metal mining and quarrying also used more of this class of explosives than in the previous year. Coal mining is the chief consumer of permissible explosives; the figures for 1933 showed that bituminous-coal mining used a larger quantity than in 1932, and that anthracite mines also showed a small increase. Although a net increase of less than 1 percent in consumption was reported for black blasting powder, large increases in use of this class of explosives were reported for metal mining, miscellaneous types of work, and bituminous-coal mining. (See table 1.)"

Nov 1, 1934

By Edwin B. Cook

Studies of flame and combustion phenomena at the Bureau of Mines have been facilitated by computer evaluation of the thermodynamic properties of gases formed by constant-pressure burning.4 5 This report is the sixth of a series6-10 presenting results of such calculations; it deals also with constant-volume deuterium-air flames.

Jan 1, 1961

By K. L. Paciorek

The primary objective of this program was to determine the toxic fume and fire hazard of elastomeric noise abatement materials with a limited effort expended on the evaluation of specific treatments applied to mine timbers. Under the conditions employed, for a dimethyl silicone rubber, formaldehyde presented the major toxic threat; acrolein was the main toxic species for both polyester and polyether urethanes and an acrylonitrile-butadiene-styrene resin; in the case of flame-retardant styrene-butadiene rubber compositions, hydrogen chloride, and in the case of PFA-treated timber, furfural, were the major toxic compounds. Of the materials studied, the flame-retardant styrene-butadiene rubbers presented the greatest toxic hazard. The generated data have been reduced to toxic load tabulations amenable to employment for potential hazard assessment.

Jan 1, 1982

By Kenneth M. Earl

This report describes the results of a field study conducted by the Bureau of Mines during 1956 and 1957 on manganese-and iron-bearing mineral deposits in the southern district of Aroostook County, Maine. The work was undertaken to determine the extent of deposits largely concealed under glacial drift and to obtain subsurface samples for manganese mineral identification and research in ore dressing and extractive metallurgy. The investigation was confined to the Westford Hill-Daggett Hill area in Hodgdon Township and to the Stewart prospects and vicinity in Linneus Township. Over 50 magnetic anomalies were mapped by magnetometric surveys in the Westford Hill-Daggett Hill area, Hodgdon Township. The largest anomaly, as outlined by the 1,000-gamma contour, indicates a deposit 3,200 feet long with a maximum width of 350 feet. The smallest anomaly measures about 10 feet wide by 25 feet long.

Jan 1, 1962

By R. F. Tenney

This report has been prepared because little detailed information has been published on the production and use of anthracite producer gas for industrial-process and brick-kiln heating. To obtain this information, an investigation was conducted by the Federal Bureau of Mines in cooperation with a building-brick manufacturer (firing both periodic and tunnel kilns with anthracite producer gas) and with a manufacturer of anthracite-gas producers. In addition to a study of available plant records, 2 weeks was spent in systematic observation and measurement during regular operation of the Hazleton Brick Co. plant, Hazleton, Pa., in July 1953. This report presents the results of this investigation and a description of producer and periodic-kiln equipment, operating procedures, and labor requirements. A summary of the conditions of producer and kiln operation is given for the 2-week observation and for the 11 preceding months. The two 10-foot standard anthracite-gas producers consumed 301 tons of Rice and Buckwheat No. 1 anthracite, as delivered, averaging over 13,000 B.t.u. per dry pound during the 2-week period, with a producer hot-gas efficiency of 95 percent, at an average gas offtake temperature of 5400 F. The yield of gas5/ of 153 gross B.t.u. per cubic foot amounted to 140,000 cubic feet per ton of fuel as fired, or 73,500 cubic feet per kiln heating hour, which was sufficient for kiln requirements.

Jan 1, 1960

By P. S. Jacobsen

In 1960 over 93 percent of the coal cleaned mechanically in the United States was cleaned in processes that utilized water or dense-medium suspensions of fine solids in water. Thus, in the process of removing deleterious ash-forming and sulfur-bearing minerals, another deleterious substance--water-- is added to the coal. The subsequent removal of the water from the coal, and the concomitant recovery of the coal from the water, is not troublesome in the sizes coarser than 1/4-inch. In the finer sizes, however, it is a difficult procedure that often costs more than the original washing operation. Because of the importance of liquid-solids separation in coal preparation, the Bureau of Mines has a continuing program of research in this field. The objective is to make available information on the performance characteristics of various types of equipment available for liquid-solids separations, thus promoting the wise selection of equipment for specific applications, and, thereby, more effective processing of coal. Results of work on flocculation as an aid to filtration5 and the sieve bend screen6 have been published. The present investigation of the screw-type classifier operating in combination with the cyclone was undertaken primarily because such classifiers are comparatively new to coal preparation and information on their performance is not available. The cyclone has become well-known since its introduction in this country by the Bureau of Mines in 1948.7 Use of the cyclone in conjunction with the screw-type classifier represents an attempt to provide the maximum recovery of solids at minimum moisture content.

Jan 1, 1962

By Todd M. Ruff

Researchers at the National Institute for Occupational Safety and Health are investigating technologies that could be used to detect objects, small vehicles, and pedestrian workers that may be in the blind areas of haulage equipment used in mining and construction. A detection system that warns the equipment operator that there is an obstacle nearby could prevent collisions and save many lives each year. One popular technology for collision warning systems is radar. Several different types of radar have been tested in the laboratory and on mining equipment. Early in the study, questions arose concerning the best way to test radar systems. Many factors affect the performance of radar, including the size, shape, and composition of the object that is to be detected; the height of the radar antenna(s); and the relative motion of the radar system and/or object. This report discusses several different test procedures and test targets and recommends methods to determine how effective a radar system will be in detecting a person near heavy equipment.

Jan 1, 2002

By Arthur L. Miller

Recent studies suggest that trace metals emitted by internal combustion engines are derived mainly from combustion of lubrication oil. This hypothesis was examined by investigation of the formation of particulate matter emitted from an internal combustion engine in the absence of fuel-derived soot. Emissions from a modified CAT 3304 diesel engine fueled with hydrogen gas were characterized. The role of organic carbon and metals from lubrication oil on particle formation was investigated under selected engine conditions. The engine produced exhaust aerosol with log normal-size distributions and particle concentrations between 105 and 101 cm-3 with geometric mean diameters from 18 to 31 nm. The particles contained organic carbon, little or no elemental carbon, and a much larger percentage of metals than particles from diesel engines. The maximum total carbon emission rate was estimated at 1.08 g h-1, which is much lower than the emission rate of the original diesel engine. There was also evidence that less volatile elements, such as iron, self-nucleated to form nanoparticles, some of which survive the coagulation process.

Jan 1, 2007

By L. M. Burman

The phase-boundary pressure required to maintain a natural hydrocarbon fluid in a single phase must be considered in planning the recovery of reservoir liquids by miscible-phase processes. The change in the phase-boundary pressure at reservoir temperature that results when a light component or a mixture of light components is added to a reservoir fluid is an especially important consideration. The cricondenbar pressure (maximum phase-boundary pressure) and the critical pressure are unique correlated pressures that have been utilized to calculate the change in phase-boundary pressure that may result when the composition of a reservoir liquid is altered by an additive. In this study one reservoir oil and three gas-condensate fluids are used as examples. Correlations pertaining to the critical and cricondenbar states in chapters 4 and 5 of Bureau of Mines Monograph 10 (3)5 were used to demonstrate how butane and lighter components added to these reservoir fluids affect their phase-boundary pressures.

Jan 1, 1962

By Wing G. Agnew

The first six Reports of Investigations in this series , pertaining to the investigation of stemming at the Mount Weather Testing Adit, dealt with ( 1 ) the dust produced by blasting , ( 2) the effect of stemming upon gases generated by blasting , ( 3 ) the relative advantages and disadvantages of different types of stemming and no stemming when used with 60 - percent ammonia gelatin dynamite , (4) the length of stemming material through which a primer will fire and detonate a charge of dynamite , ( 5) comparison of dust and gases produced when blasting charges of dynamite in drill holes , bombs, and mud - cap shots , and ( 6 ) the relative advantages and disadvantages of different types of stemming and no stemming when used with 40 - percent ammonia gelatin dynamite .

Oct 1, 1943